class Human:
    def speak(self):
        pass

    def walk(self):
        pass

class Son(Human):
    def speak(self,words):
        print('我想说今天是%s'%words)

    def walk(self,steps):
        print('今天走了%s步'%steps)

if __name__ =='__main__':
   test=Son()
   test.speak('2月23号')
   test.walk('8000')
